A collection of random thoughts from someone who has spent much of their life trying to bring illumination where there is darkness and ignorance. Like Prometheus, the author has found that no good deed ever goes unpunished!

Not surprisingly, they did not publish the questions they asked, which would have given us the opportunity to analyze their survey for systematic bias. What they did do was publish the raw data, which allows us to analyze their results.

Assessing the survey:

When looking at a survey, the first step is to examine the survey structure - particularly the questions, but also the area covered and population contacted - for any flaws or biases. This survey was conducted in nine counties of California and Oregon - generally the more populous counties - which gives it a West Coast bias. Since autism, ADD/ADHD, asthma and diabetes do not show a coastal preference, this bias should not create a serious problem for the survey.

Next, looking at the data, we need to see if there are age or sex biases. Since the data do not include a detailed breakout of the ages year-by-year, it is impossible to analyze for age biases, but the sex ratio (52% male, 48% female) - although it is close to the US Census Bureau data for that age range - shows a statistically significant difference from the US population.

Looking at the sex ratios of the unvaccinated and vaccinated (both fully and partially) groups, the differences are not statistically significant, so the imbalance in the sex ratio is equal in both groups.

It would be helpful to know how many people they had to call to get the number of responses they did - this gives a good measure of how skewed the responses might be. The higher the percentage of people refusing to take the survey, the more likely that the people who do answer are not a representative sample of the population.

Unfortunately, we are not provided this information, so we have no way of knowing how many of the people who were called hung up or otherwise refused to participate, which makes it impossible to know the degree of participation bias. We'll just have to soldier on.

Assessing the data:

Looking at the data, one thing that pops up as an immediate red flag is that the prevalence of autism is greater than the prevalence of PDD-NOS. This is an inversion of the usual finding, which is that autism (with stricter diagnostic criteria) is less common than PDD-NOS (which is essentially some of the criteria for autism but not enough to diagnose autism). This suggests that the people involved in the survey may not be asking the right questions.

Looking a bit closer, the prevalence of the autistic spectrum disorders is way out of line with the most recent data. In February of this year, the CDC published a report on the prevalence of autism in six states. This prevalence was widely reported and was frequently cited as more evidence of the "autism epidemic" by the chelationistas, so it should be familiar.

This CDC report found that the prevalence of autistic spectrum disorders ranged from 4.5 to 6.5 per 1000 children, which would be 0.45 - 0.65%.

The GR survey found that the prevalence of autistic spectrum disorders was 4.7% in their overall sample and ranged from 1.3% (female, fully vaccinated) to 8.4% (male, partially vaccinated). This is nearly ten times the CDC prevalence.

To put the number into perspective, the CDC data say that somewhere between 1 in 222 to 1 in 154 children have an autistic spectrum disorder. The GR survey would suggest that 1 in 21 children have an autistic spectrum disorder. Ridiculous!

Clearly, there is a serious problem with this survey.

This is reminiscent of the infamous Holmes et al study, which found that their control subjects had over ten times the amount of mercury in their hair than the NHANES study found in children of similar ages less than a year later.

Now, the people who ordered this survey may argue that it's the difference between the two groups - not the absolute number - that is important. This sounds reasonable, but it isn't. There is no way to know if the degree of error is the same in all the groups.

If the "over-reporting factor" is only 5% less in the "unvaccinated" group than in the other groups, the difference between the groups disappears. This completely invalidates the "results".

So, with this glaring evidence of error, is there any point in looking any further?

No, not really. But we should examine the major claim being made about the survey results, just to be thorough.

"Vaccinated boys have a 155% greater chance of having a neurological disorder like ADHD or autism..."

Let me start off by saying that - even if the survey was accurate, which it clearly is not - an increase in autism and ADD/ADHD would not constitute an increase in "neurological disorders", which their conclusion implies. There may, in fact, be neurological disorders (e.g. measles inclusion-body encephalitis) that are reduced by vaccination. So, even without looking at the data, this assertion is pure nonsense.

But, back to the survey data.

To get a statistically significant difference between the unvaccinated and vaccinated boys, they had to lump the partially vaccinated and the fully vaccinated boys together and they also had to lump autism, PDD-NOS, Asperger's syndrome, ADD and ADHD together.roups, with the partially and fully vaccinated boys having - as a group - 55% more reported "neurological disorders".

However, if you look at the "autistic spectrum disorders" by themselves, there is no statistically significant difference between unvaccinated and vaccinated (partially plus fully) boys.

Curiously, there is a statistically significant difference between the partially vaccinated boys and both the unvaccinated andfully vaccinated boys. Partially vaccinated boys have a higher prevalence of autistic spectrum disorders than either the unvaccinated or fully vaccinated boys.

Now, if you want to show that an exposure causes a disorder, it is generally a good idea to show a dose-response relationship. In the case of this survey, a little vaccination is worse than none or a lot. This doesn't sound like a dose-response relationship to me.

Well, so the autism-vaccine connection doesn't work - how about ADD/ADHD?

Out of 17,674 children in the survey, 1,875 had either ADD or ADHD. That works out to a prevalence of 106 per thousand or 10.6%.

That seems a bit high.

If you look at the USDE data from 2005, the percentage of children ages 4 - 17 years with "other health impairment" (the catch basin for ADD/ADHD and many other disorders) was 9.5 per thousand or 0.95%. This is over ten times lower than reported in the GR survey. And remember - the USDE "other health impairment" category includes a variety of diagnoses other than ADD/ADHD.

So, it seems that there are some serious problems with the GR survey data. I don't know what the cause of the problem is (although I have my suspicions), but one thing is painfully clear:

22 Comments:

Ms. Clark said...

For some reason Handley and the malicia are not screaming that they found so many autistic children. And they really are silent on the fact that they found so many autistic unvaxed children! I thought it was not possible for unvaxed kids to become autistic.

My guess would be that they are keeping quiet in the hope that nobody in the media notices that their survey numbers don't add up.

I doubt that they are interested in convincing anybody in the scientific or skeptical communities. I suspect that they see that they are about to lose in the courts and are positioning themselves for a legislative end-run around scientific reality.

One thing that I didn't mention in the blog post was that their survey also "demonstrated" that unvaccinated kids had a statistically significant increased risk of juvenile diabetes.

I didn't mention it because I had already beaten the survey as much as I could stand and because it is just as worthless a finding as any of their conclusions.

I had no trouble last night finding a link to GR's pdf document which explained the phone survey questions in detail. [ http://www.generationrescue.org/pdf/questions.pdf ] Perhaps you were in a hurry.

I think it would be a reasonable guess that asthma & diabetes were included because they are also conditions caused by impaired immune systems - info that could be helpful because there is enough scientific data to support immune dysfunction involvement in neurological disorders.

FWIW, my son who would be classified as PDD-NOS has never been formally diagnosed. (His pediatrician blew off my concerns about his delayed speech, etc - novel, eh?) However, the speech pathologists & other therapists that we have consulted agree that would likely be his diagnosis if we decided on the need for a formal label.

Such diagnoses can adversely impact medical insurance and other parents I have talked to also worry about the impact on their child's future so I've often wondered how many other neurologically damaged kids are out there that aren't on the radar screen.

Why not put this whole vaccination argument to rest by doing a real study? One that is funded with no strings - or perks FTM - attached, done by scientists with no blatant conflicts of interest.

Considering the history of this debate and the unlikelihood of its dying following the current trajectory surely it would be money worth spending. Yes, there would probably still be a few hold outs, but most of us are looking for reassurance that doesn't require quite so much trust in entities that have already proven they don't deserve it.

Thank you for directing me to the question list - I had seen that list but was assuming that there was a more detailed follow-up. If this was, indeed, the extent of the telephone survey, then it was completely worthless.

The "word on the web" is that there was a "health battery" of questions asked of parents who responded, which I don't see on this list. I still have to believe that there was a more in-depth follow-up, because what I see here isn't worthy of a professional market research company. That said, it could explain the poor quality of the data gathered.

You and others have argued that what is needed is a "real study" to "put this whole vaccination argument to rest". I assume that you discount those studies that have already been done as "biased", "corrupt" or "tainted by the funding source". For what it's worth, real studies have been done that show no discernible link between vaccinations and autism.

The real problem, as I see it, is that none of the "believers" - people like yourself - will trust any study that fails to show a connection. Many have been done and they have all been dismissed as being "flawed", "biased", "corrupt" or "tainted". Strangely enough, the same charges are never leveled against those "studies" - such as the Geier and Geier VAERS studies - that really are flawed, biased and tainted.

In closing, you stated that

"...most of us are looking for reassurance that doesn't require quite so much trust in entities that have already proven they don't deserve it. "

If you want reassurance, I would suggest that you read the transcripts of the ongoing Omnibus Proceedings. That should "reassure" you that the people who are claiming a connection between vaccines and autism haven't done a very good job researching their claims. Perhaps you should examine the trust you place in the people who are telling you that vaccines cause autism. That trust is almost certainly misplaced.

When I read about the amazing numbers of children with autism discovered in this survey, I wonder about the methodology. Where did they get the phone lists, I wonder? Perhaps they used the membership lists of some kind of autism group as a starting point? Maybe they thought that they wouldn't find any unvaxed kids amongst the family and friends of people with autism? After all, if they just phoned people at random, they would have to call a huge number to find a reasonable number of kids with ASD - say 150,000 to find 1000 kids with autism. That would be very expensive.

I missed the reference to "golf clap". I don't golf and am - as my children remind me on a nearly daily basis - not up with current culture.

Our department uses StatGraphics, but I did a lot of the statistical work on this "project" using nothing more advanced than a pad of paper and a hand-held calculator.

That's what drove me a bit crazy - it doesn't take sophisticated statistical software to see that this survey is flawed. Someone with a fair grasp of statistical analysis could see it. One wonders what the survey company said to its clients.

I sincerely doubt that there are actually that many Geier groupies and I am certainly not one. I have not leaned on them for "proof" of my concerns about the current vaccination program. Note that I use the word CONCERNS. That's not the same as anti-vaccine. Think of it as a spectrum(!) and not everyone is at one extreme end or the other.

I do not understand why this hub you belong to insists on lumping everyone who asks questions into a category that appears to be "stupid morons who should just trust the authorities & stop asking questions". It's so counter-productive - makes it hard for people to be open to your message when they have their defenses up. And it's frustrating trying to find a forum in which to discuss ideas openly when you have to worry about getting slammed for expressing doubts or thinking outside the mainstream box.

I am not anti-vaccine; I am anti-lemming. I worked in pharmacy for a fair amount of time. I witnessed the guinea pig period after the chicken pox vax (shingles showing up in teenagers & ineffective titers to boot - and how deadly is CP?) & the disastrous rotavirus vax (why wait for the virus to kill your child when we can do it now & save time?) were released. I'm sure the so-called "big pharma conspiracy" is not a back room collaboration as some seem to think - it's just plain & simple primitive human greed. The hard data supports that pretty readily.

Corruption in big business is not new or novel - remember learning about yellow journalism or muckraking in history class? It still boggles my mind to think that people would actually sell products for consumption knowing that there were things in there that they wouldn't dream of eating or feeding to their own children.

So when, for example, J&J pays for a study that clears RhoGAM, it shouldn't be that hard to understand why some people are suspicious. In fact, as I told you before, the professors I had in pharmacy college specifically told us to be suspicious of such studies. And there are apparently credible studies that have found potential links between thimerosal & tics as well as ADHD. (Apparently credible because they are some of the ones being used to "prove" that thimerosal doesn't cause autism, yet tics and attention deficit are frequently comorbid)

I was following the Omnibus transcripts for a while but they are too long - I can't keep staying up till 3 in the morning. I found the information from both sides to be very interesting, but the case isn't very helpful to me because I don't believe that it is as simple as 'MMR causes autism' or 'Thimerosal causes autism' and I don't really understand why they chose that tack. I think that's too simplistic. I believe autism is caused by a domino or maybe even a cascade effect.

I believe that our kids are born with some form of immune system damage that for some requires one hit, for others might take multiple hits, that then sends them over the edge so to speak. So when a family like mine & my DH's that up to this point have had people with what could be considered autistic traits but no dysfunction becomes immunologically vulnerable, and then receives an immunological slam, then we have neurological damage that looks like what is considered to be on the autistic spectrum.

I was (like so many mothers of autistic children) recently diagnosed with autoimmune thyroiditis and as I have researched the issue of autoimmunity discovered that there are so many potential immunological slams. All it takes is something capable of causing significant inflammation. (And whatever has affected my immune system has either directly or indirectly affected those of my children as well - all 5 have some degree & form of immune dysfunction)

Note that Michelle Cedillo may have had some signs of autism, but she was doing okay developmentally till she got her MMR. If you look at the mfr's info, high fever less than a week following the vax as hers was is considered related (They say up to a month but typically 5 - 12 days. I believe they said Michelle's was 5 days later). The suggestion that she might have picked up the flu is unlikely as it was an atypical fever for flu, but not for an MMR reaction. The possibility exists, but the probability points to the vax. If my thinking is not off base, then Michelle was immunologically vulnerable when she got the MMR. The development of an autoimmune gut condition would be consistent with the ongoing inflammation of the gut which developed as part of that initial reaction and never really returned to normal (similar symptomology to irritable bowel syndrome which we now know is caused by dysbiosis and it would certainly follow under such circumstances). I think they would have a pretty solid win if they went after the case on the basis of her IBD, but I don't think this is strictly about compensation...

I don't recall ever saying that you were a "Geier groupie", nor do I recall that acusation being made by any of the other commenters.

As for "...lumping everyone who asks questions into a category that appears to be 'stupid morons who should just trust the authorities & stop asking questions'.", I think that you are overstating your point.

I don't see that anyone on the Autism Hub is opposed to answering question or even debating the issues. I am certainly open to questions, but I also don't feel the need to answer what are clearly rhetorical questions, questions posed only to make a statement.

As I mentioned in our e-mail exchanges, I don't see that you are asking questions. It appears, instead, that you are throwing out challenges. Questions indicate an open mind, challenges are generally a sign that someone has already received all the information they need.

While there are people on the Hub who relish taking on challenges, I find it somewhat tedious to keep going over the same group with every person who arrives full of received knowledge from the chelationistas. And make no mistake about it - your "arguments" are the exact same ones that I've received and answered time and time again for over two years.

I also make it a point to not try to reason someone out of a point of view that they did not reason themselves into. For instance, you seem quite concerned that J&J sponsored the study that eventually exonerated RhoGam; are you seriously accusing the researchers of deliberately falsifying data or are you merely saying that they are incompetent?

And given your heightened concerns about funding sources, what do you think about the Geier "studies", the Holmes "study" and many of the others that are cited?

I might also point out that I have done research funded by drug companies on numerous occasions in the past - does that make me a "Pharma Shill"? Would it change your mind if you knew that on at least six occasions, the research results showed that the drug was not effective (and they were published)?

I find concerns about research "bias" to be extremely unidirectional, and so I tend to discount them. Competence, however, is another issue.

Questions are always welcome, as are arguments, if you have some data to back up your position. Sorry to say, but simply believing that something is so doesn't make it so. People believed that the sun orbited the earth - it didn't change celestial mechanics.

Finally, I do agree with you that the Omnibus Proceedings are not about compensation (except for the lawyers) but I do believe that it is all about winning.

And the sad thing is that winning has become more important than finding the truth.

Grace - your comments are interesting and have some good points. Don't have time to respond to them all as lunchtime is over, but just want to point out one item from the hearings.

Michelle's parents have stated that they felt she was developing normally till she received the MMR, however, several experts in diagnosing autism reviewed family videos of Michelle from months previous to the MMR, and showed she was showing autistic tendencies then (NOT developing normally).

I would also like to point out that it is possibly not just a matter of Michelle's parents "feeling" that she was developing normally. My own autistic daughter met and surpassed all the milestones on the developmental charts that were available to us at that time (she was born in 2000.) However, the red flags for autism were not on the typical developmental charts at that time. We never saw a developmental chart that mentioned things like lack of shared interest, lack of pretend play, etc., until after the diagnosis. Only right now, IME, are pediatricians even becoming aware that a toddler who can speak and has normal gross motor development can still be on the spectrum. I was greatly interested to read of the videotapes of Michelle's babyhood in this trial. I would have sworn up and down, five years ago, that my child had been "normal" and that something had "happened to her." Now, I can look back at the tapes and see that she was always the person she is today. Obviously this is not the case for all individuals on the spectrum or for all parents. But I don't see how one can ignore the evidence in this case. (Unless one is just too tired and busy to actually read the facts, that is.)

Bink, that's exactly what happened in our case. My son developed "normally", except he wasn't sharing and showing at 12 months of age. Had the developmental charts been more informative, I might have caught the signs earlier. To the "untrained" eye, my son was not autistic - and maybe still wouldn't be at almost 4. But armed with the knowledge I have now, I can look back and recognize signs of autism from the time he was a newborn. Except the differences only got more pronounced after 12 months (when his language wasn't progressing at the expected pace) and at 15 months (when he started lining up toys and developing narrow interests, and doing more echolalia). I think once you're able to recognize the steady and progressive appearance of autism as part of your child's personality, you realize you can't blame a specific event that "changed" your NT child into an autistic one. The fact that my son was born after thimerosal was removed from vaccines makes it even harder for me to buy the vaccine theory.

I added a reply days ago that the system said was pending moderator approval - did you not get it or was it not approved?

[Here is a copy]Laurentius,One and One.

Maggie & Binks,I'm sorry I didn't express myself well enough. My pov is that Michelle was probably sent from a milder form of autism into a major one. I base that in part on my experience with one of my other children who is not autistic but has neurological problems & would've fit the description of AS "shadow syndrome" around 4 or 5 though not before & he did pretty much grow out of it. Now at 15 he would probably qualify for NVLD and definitely for Tourette's. It took me a while to be sure, but all of his symptoms, not just the tics, wax & wane according to the status of his immune system.

Prometheus,It is to your credit that you are actually one of the least incendiary & least polarizing on the hub, but you do still slip into it from time to time. I was referring to the use of words like "chelationistas" and "antivaccine", for example, as a generalization for anyone who makes a statement or asks a question that is construed as oppositional. But more than that is the belittling tone with which you seem to speak of "believers" as you put it (As if we are all believers in the same thing? And does that then mean that since you yourself are not a believer, you don't believe in anything? Do you just stand on the sidelines chucking stuff at the people trying to wade their way thru this mess?) It is difficult enough for a person to admit when they are wrong, but when we perceive that there are people who will gloat at our failure, it becomes harder still.

Additionally you keep bringing up the work of people like the Geiers & others even though I don't. That's akin to debating against stem cell research on the basis of the credibility of that discredited Korean scientist who lied about his research. There are suspicious & questionable characters on BOTH sides of the debate. All that testifies to is the foibles of human beings. And the need to look beyond their research. These people are road hazards in the search for truth. Generally we go around or avoid road hazards rather than making a U-turn.

I was working from the EPA report on mercury. That seemed a reasonable common ground. Why does that not work for you?

I have not said that thimerosal causes autism. I said that my son with PDD-NOS symptoms closely fits the description of neurological damage caused by mercury provided by the EPA's report and he was exposed to aerosolized mercury while I was 5 mos pregnant because I had an amalgam replaced. So based on the data that I have looked at from the EPA report and the research articles at PubMed, etc, I therefore believe that my son's autistic condition was caused by mercury. My question then is if mercury in that form can cause symptoms resembling autism, then why should we believe that thimerosal cannot? That is a question not just a position.

I understand the exasperation with answering the same questions over & over again (I have 5 children after all!). It does get old. But when people are new to the discussion, you cannot simply say "I answered that already" and expect them to say "Oh, okay, never mind." It's not just unrealistic; it's unreasonable particularly given in a format that invites discussion by its nature. If you're tired of repeating yourself, then you might consider putting things where they can be easily found by newbies as other bloggers do.

It is frustrating to be told that you have all the answers but your audience must seek them out of your archives for themselves. It also becomes a credibility issue for you. I once located a paper on the www by a man who claimed to be completely refuting another PhD whose work I was researching (not autism, something totally unrelated). I read thru pages & pages of his tedious work in which all he did was rant about how easily he had disproved the PhD on this and that, etc. He sounded smart and promising, but turned out to be all hot air - there was no substance to his claims.

I'd love to find a forum for open discussion of these things, but have yet to find one. In this statement of yours, "the sad thing is that winning has become more important than finding the truth", we could not be in more complete agreement. I am searching, however crudely, for the truth. If there is any way to help my children, I want to find it. And I want to protect our family line from further damage.

I did do a search of your blog. The word "autoimmune" brought me to this - http://photoninthedarkness.blogspot.com/search?q=autoimmune & in it you included this helpful link - http://www.crossroadsinstitute.org/newsletter/nlarticles/aug05/singhautism.html(BTW, in response to something you asked in your article questioning the use of a supplement that would stimulate the immune system, this was in the Singh article, "Immune interventions can produce immune modulation-a state of suppression or stimulation. Depending on the nature of the immune abnormality, the goal of therapy should be to normalize or reconstitute the immune response..." The argument being that if you have an overbalance towards suppression, then a stimulant could theoretically swing it back the other direction to bring it back in balance. I have no idea of the validity of this line of reasoning; simply letting you know it's there. Singh does not sound like he would agree.)

What do you think of VK Singh's research? Perhaps this will influence your opinion of him? - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=15316135&ordinalpos=4&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum & http://www.blackwell-synergy.com/action/showFullText?submitFullText=Full+Text+HTML&doi=10.1111%2Fj.1399-3038.2006.00480.x but then there are several like this - http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=12849883&ordinalpos=20&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum

[After I wrote this I did find a critique of some of Singh's work on measles autoimmunity from some Brits in 2002, but have no idea where it all stands since then and would still be interested in your opinion of him and his theories]

It is occasionally my intent to be inflammatory and polarizing. I feel that a "balanced" approach to utter nonsense only serves to prolong the belief that the nonsense has any validity.

I use the term "chelationistas" because it is simpler than saying "people who believe that autism is caused by mercury poisoning and cured by chelation".

As for calling a position "anti-vaccination", I think you'll have to admit that many of the folks who were originally "anti-thimerosal" (was anybody "pro-thimerosal"?) have now broadened their attack to include all vaccinations and their contents (live virus, dead virus, preservatives, adjuvants, etc.). Again, the term "anti-vaccination" may omit some of the nuances of their individual positions, but it's a lot easier to type.

As for my atitude toward "believers", I suggest that you look at my posting on "belief" (http://photoninthedarkness.blogspot.com/2007/02/word-play-believing.html). "Believers" are simply people who emphatically repeat statements that they do not fully understand, based on the fact the they "believe" the person who told it to them originally.

As an example, let's examine your question:

"My question then is if mercury in that form can cause symptoms resembling autism, then why should we believe that thimerosal cannot?"

The first step in answering your question is to point out that - despite the paper by Bernard et al - mercury poisoning looks nothing like autism. It is significant that none of the authors on that paper had ever seen mercury poisoning and were simply comparing lists of symptoms and drawing unsupported comparisons.

Having thus established that mercury poisoning and autism may not (and, in fact do not) have similar presentations, how would you support your belief that your child's autism was caused by mercury in your dental amalgam?

I would be interested to know if this information had any effect on your beliefs about autism.

I don't mean to beat you up over this, but your "belief" that a paper published in Medical Hypotheses - the National Enquirer of scientific journals (see its instructions to authors) - was accurate has led you to "believe" other things that may also not be accurate.

This is not a condemnation of you or the thousands of other parents who are taken in by this sort of thing. I suspect that even the authors of this abysmal paper "believe" what they are saying. They simply lack the knowledge to know that they are wrong.

If you would like to start a discussion of a topic, then by all means start a discussion. This 'blog may not be the best forum for it, since the comments are moderated and therefore are not updated in real time. That tends to slow down the give-and-take necessary for a good discussion.

In addition, I would suggest that if you want an answer to a question, that you phrase it as a question rather than a challenge. It's really not my place to prove somebody wrong (as in "Show me why mercury doesn't cause autism") - it's actually their job to prove themselves right. I have grown tired of trying to reason people out of positions they did not reason themselves into, and so I rarely take the time to try to argue with a "believer". "Seekers", on the other hand, can have all of my spare time.

As for Dr. Singh's autoimmunity hypothesis of autism, I feel that it has some merit - as a hypothesis - but still lacks any significant data to support it. When (or if) he comes up some data to support an immune component to either the cause of autism or the persistence of autism, then I will be all ears.

One of the many problems with most of the hypotheses of autism causation is that they confuse correlation with causation.

To explain further:

Just because an autistic child - or even most autistic children - have some feature (autoimmunity, large heads, signs of oxidative stress, low serum porcelain, etc.), it does not follow that this (or these) features are indicative of the cause of autism. They may simply be other features of autism. In other words, the autoimmunity (if that is shown) or oxidative stress (ditto) may be the result of autism, not the cause.

If you go down to the local grade school and compare shoe size and reading ability, you will find a very strong correlation. Does this mean that a bigger pair of Nikes will make your child a better reader? Of course not! This illustrates just one of the reasons that correlation does not equal causation.

I don't intend to "put down" or "disrespect" parents who are struggling with the question of what to do to help their autistic child - I have nothing but sympathy for them. I also understand how appealing it is to have someone tell you, "I know what the problem is and what to do about it." All of us parents (or almost all) would like to have an answer and a plan of treatment. However, there is little point to getting the wrong answer and the wrong plan.

I hope that this helps a bit - and if it doesn't, just ask a question.

You didn't link to the article - it just happens to be the article most commonly cited to "prove" that mercury can cause autism.

There have been a number of articles purporting to connect mercury and autism, but they have either failed to show that the results of mercury exposure are connected to autism or they have failed to show a causal relationship (or both).

I'm not fundamentally apposed to a causal link between mercury and autism, I just don't see any convincing data to support it.

I am really confused. I have given you several links which I am providing to show you where I am coming from - some of the data that appears to support why I believe as I do as you requested. You keep addressing studies and people who I have not brought up. I would appreciate it if you would look at the links I am citing instead of the ones that you seem to expect me to cite.

I checked the EPA document - I even used a text search. I didn't find any reference to autism in the entire document. Nor did I find any reference to PDD-NOS, ADD/ADHD or Asperger's syndrome.

I did find reference to erethism and the classical signs and symptoms of mercury poisoning. One of the hallmarks of mercury poisoning - one so universally found that it is the basis of the most sensitive tests for mercury-induced neurological damage - is tremor. This is a symptom not often found in autistic children.

If you read this list and found similarities to autism, then you have made the same error that Bernard et al made.

The Rice paper you cite in your second link is another good example of taking something that has nothing to do with autism and trying to make it fit. Rice found decreased sensitivity to touch in monkeys dosed with methyl mercury (which is very different from the ethyl mercury released from thimerosal or elemental mercury released from dental amalgams). I am not aware of any study showing that autistic children have reduced sensitivity to touch. Reduced pain sensitivity has been claimed, but not reduced sensitivity to touch.

The Grandjean and Landrigan paper that your third link points to starts off by saying that the causes of autism are unknown. They are advocating a different approach to regulation of chemicals - they are not claiming that mercury causes autism.

Grandjean also published a comprehensive study on the effects of prenatal methylmercury exposure (from fish) in 1022 children born in the Faroe Islands. They did not find autism, despite markedly elevated methyl mercury intakes.

Now, I'm sure that you will point out that the authors of these studies have "biases" or "conflicts of interest", but if you would apply that stringent a filter to all that is published about autism, the sum total of "acceptable" studies would be exactly zero.

In fact, in almost all of the studies that claim to find a connection between autism and mercury, the authors have worse biases and conflicts of interest.

My intention is not to demean your efforts, but to point out that - like many people - you are making "connections" that do not exist.

I think that we have beaten this particular horse enough in the comment section. If you have further issues to discuss, bring them up off-line.